Multifocal ophthalmic lenses

Abstract

The invention provides multifocal lenses for correction of presbyopia. Each of the lenses of the invention provide both distance and near vision correction by providing both a first multifocal region, a monofocal region, and a second multifocal region within the same lens.

Description

FIELD OF THE INVENTION[0001]The invention relates to ophthalmic lenses. In particular, the invention provides lenses that incorporate more than one optical power, or focal length, and that are useful in the correction of presbyopia.BACKGROUND OF THE INVENTION[0002]As an individual ages, the eye is less able to accommodate, or bend the natural lens, to focus on objects that are relatively near to the observer. This condition is known as presbyopia. Similarly, for persons who have had their natural lens removed and an intraocular lens inserted as a replacement, the ability to accommodate is totally absent.[0003]Among the methods used to correct presbyopia is the mono-vision lens system in which a person is fitted with, and wears, two contact lenses; one lens for distance vision and one lens for near vision. The mono-vision system permits the wearer to distinguish both distance and near objects, but is disadvantageous in that a substantial loss in depth perception results.[0004]Another...

AI Technical Summary

Benefits of technology

The invention provides lenses that can correct presbyopia by incorporating both multifocal and mono-focal regions within the same lens. These lenses offer improved depth perception and reduced interference between near and distance objects, while also addressing the disadvantages of known lenses. The lenses have a unique design that combines the benefits of both multifocal and mono-focal lenses, providing better vision for both distance and near objects. The technical effects of the invention include improved vision for presbyopic individuals and reduced interference between near and distance objects.

Problems solved by technology

As an individual ages, the eye is less able to accommodate, or bend the natural lens, to focus on objects that are relatively near to the observer.

Similarly, for persons who have had their natural lens removed and an intraocular lens inserted as a replacement, the ability to accommodate is totally absent.

The mono-vision system permits the wearer to distinguish both distance and near objects, but is disadvantageous in that a substantial loss in depth perception results.

However, multifocal contact lenses are problematic in that they expose the wearer's retina to two images at once, one in and one out of focus.

However, such lenses are problematic for distance vision.

As a result, the out of focus near images are inverted and interfere with the image of the distant object.

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